1 //===- ELF.cpp - ELF object file implementation ---------------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #include "llvm/Object/ELF.h" 10 #include "llvm/BinaryFormat/ELF.h" 11 #include "llvm/Support/DataExtractor.h" 12 13 using namespace llvm; 14 using namespace object; 15 16 #define STRINGIFY_ENUM_CASE(ns, name) \ 17 case ns::name: \ 18 return #name; 19 20 #define ELF_RELOC(name, value) STRINGIFY_ENUM_CASE(ELF, name) 21 22 StringRef llvm::object::getELFRelocationTypeName(uint32_t Machine, 23 uint32_t Type) { 24 switch (Machine) { 25 case ELF::EM_68K: 26 switch (Type) { 27 #include "llvm/BinaryFormat/ELFRelocs/M68k.def" 28 default: 29 break; 30 } 31 break; 32 case ELF::EM_X86_64: 33 switch (Type) { 34 #include "llvm/BinaryFormat/ELFRelocs/x86_64.def" 35 default: 36 break; 37 } 38 break; 39 case ELF::EM_386: 40 case ELF::EM_IAMCU: 41 switch (Type) { 42 #include "llvm/BinaryFormat/ELFRelocs/i386.def" 43 default: 44 break; 45 } 46 break; 47 case ELF::EM_MIPS: 48 switch (Type) { 49 #include "llvm/BinaryFormat/ELFRelocs/Mips.def" 50 default: 51 break; 52 } 53 break; 54 case ELF::EM_AARCH64: 55 switch (Type) { 56 #include "llvm/BinaryFormat/ELFRelocs/AArch64.def" 57 default: 58 break; 59 } 60 break; 61 case ELF::EM_ARM: 62 switch (Type) { 63 #include "llvm/BinaryFormat/ELFRelocs/ARM.def" 64 default: 65 break; 66 } 67 break; 68 case ELF::EM_ARC_COMPACT: 69 case ELF::EM_ARC_COMPACT2: 70 switch (Type) { 71 #include "llvm/BinaryFormat/ELFRelocs/ARC.def" 72 default: 73 break; 74 } 75 break; 76 case ELF::EM_AVR: 77 switch (Type) { 78 #include "llvm/BinaryFormat/ELFRelocs/AVR.def" 79 default: 80 break; 81 } 82 break; 83 case ELF::EM_HEXAGON: 84 switch (Type) { 85 #include "llvm/BinaryFormat/ELFRelocs/Hexagon.def" 86 default: 87 break; 88 } 89 break; 90 case ELF::EM_LANAI: 91 switch (Type) { 92 #include "llvm/BinaryFormat/ELFRelocs/Lanai.def" 93 default: 94 break; 95 } 96 break; 97 case ELF::EM_PPC: 98 switch (Type) { 99 #include "llvm/BinaryFormat/ELFRelocs/PowerPC.def" 100 default: 101 break; 102 } 103 break; 104 case ELF::EM_PPC64: 105 switch (Type) { 106 #include "llvm/BinaryFormat/ELFRelocs/PowerPC64.def" 107 default: 108 break; 109 } 110 break; 111 case ELF::EM_RISCV: 112 switch (Type) { 113 #include "llvm/BinaryFormat/ELFRelocs/RISCV.def" 114 default: 115 break; 116 } 117 break; 118 case ELF::EM_S390: 119 switch (Type) { 120 #include "llvm/BinaryFormat/ELFRelocs/SystemZ.def" 121 default: 122 break; 123 } 124 break; 125 case ELF::EM_SPARC: 126 case ELF::EM_SPARC32PLUS: 127 case ELF::EM_SPARCV9: 128 switch (Type) { 129 #include "llvm/BinaryFormat/ELFRelocs/Sparc.def" 130 default: 131 break; 132 } 133 break; 134 case ELF::EM_AMDGPU: 135 switch (Type) { 136 #include "llvm/BinaryFormat/ELFRelocs/AMDGPU.def" 137 default: 138 break; 139 } 140 break; 141 case ELF::EM_BPF: 142 switch (Type) { 143 #include "llvm/BinaryFormat/ELFRelocs/BPF.def" 144 default: 145 break; 146 } 147 break; 148 case ELF::EM_MSP430: 149 switch (Type) { 150 #include "llvm/BinaryFormat/ELFRelocs/MSP430.def" 151 default: 152 break; 153 } 154 break; 155 case ELF::EM_VE: 156 switch (Type) { 157 #include "llvm/BinaryFormat/ELFRelocs/VE.def" 158 default: 159 break; 160 } 161 break; 162 case ELF::EM_CSKY: 163 switch (Type) { 164 #include "llvm/BinaryFormat/ELFRelocs/CSKY.def" 165 default: 166 break; 167 } 168 break; 169 case ELF::EM_LOONGARCH: 170 switch (Type) { 171 #include "llvm/BinaryFormat/ELFRelocs/LoongArch.def" 172 default: 173 break; 174 } 175 break; 176 case ELF::EM_XTENSA: 177 switch (Type) { 178 #include "llvm/BinaryFormat/ELFRelocs/Xtensa.def" 179 default: 180 break; 181 } 182 break; 183 default: 184 break; 185 } 186 return "Unknown"; 187 } 188 189 #undef ELF_RELOC 190 191 uint32_t llvm::object::getELFRelativeRelocationType(uint32_t Machine) { 192 switch (Machine) { 193 case ELF::EM_X86_64: 194 return ELF::R_X86_64_RELATIVE; 195 case ELF::EM_386: 196 case ELF::EM_IAMCU: 197 return ELF::R_386_RELATIVE; 198 case ELF::EM_MIPS: 199 break; 200 case ELF::EM_AARCH64: 201 return ELF::R_AARCH64_RELATIVE; 202 case ELF::EM_ARM: 203 return ELF::R_ARM_RELATIVE; 204 case ELF::EM_ARC_COMPACT: 205 case ELF::EM_ARC_COMPACT2: 206 return ELF::R_ARC_RELATIVE; 207 case ELF::EM_AVR: 208 break; 209 case ELF::EM_HEXAGON: 210 return ELF::R_HEX_RELATIVE; 211 case ELF::EM_LANAI: 212 break; 213 case ELF::EM_PPC: 214 break; 215 case ELF::EM_PPC64: 216 return ELF::R_PPC64_RELATIVE; 217 case ELF::EM_RISCV: 218 return ELF::R_RISCV_RELATIVE; 219 case ELF::EM_S390: 220 return ELF::R_390_RELATIVE; 221 case ELF::EM_SPARC: 222 case ELF::EM_SPARC32PLUS: 223 case ELF::EM_SPARCV9: 224 return ELF::R_SPARC_RELATIVE; 225 case ELF::EM_CSKY: 226 return ELF::R_CKCORE_RELATIVE; 227 case ELF::EM_VE: 228 return ELF::R_VE_RELATIVE; 229 case ELF::EM_AMDGPU: 230 break; 231 case ELF::EM_BPF: 232 break; 233 case ELF::EM_LOONGARCH: 234 return ELF::R_LARCH_RELATIVE; 235 default: 236 break; 237 } 238 return 0; 239 } 240 241 StringRef llvm::object::getELFSectionTypeName(uint32_t Machine, unsigned Type) { 242 switch (Machine) { 243 case ELF::EM_ARM: 244 switch (Type) { 245 STRINGIFY_ENUM_CASE(ELF, SHT_ARM_EXIDX); 246 STRINGIFY_ENUM_CASE(ELF, SHT_ARM_PREEMPTMAP); 247 STRINGIFY_ENUM_CASE(ELF, SHT_ARM_ATTRIBUTES); 248 STRINGIFY_ENUM_CASE(ELF, SHT_ARM_DEBUGOVERLAY); 249 STRINGIFY_ENUM_CASE(ELF, SHT_ARM_OVERLAYSECTION); 250 } 251 break; 252 case ELF::EM_HEXAGON: 253 switch (Type) { STRINGIFY_ENUM_CASE(ELF, SHT_HEX_ORDERED); } 254 break; 255 case ELF::EM_X86_64: 256 switch (Type) { STRINGIFY_ENUM_CASE(ELF, SHT_X86_64_UNWIND); } 257 break; 258 case ELF::EM_MIPS: 259 case ELF::EM_MIPS_RS3_LE: 260 switch (Type) { 261 STRINGIFY_ENUM_CASE(ELF, SHT_MIPS_REGINFO); 262 STRINGIFY_ENUM_CASE(ELF, SHT_MIPS_OPTIONS); 263 STRINGIFY_ENUM_CASE(ELF, SHT_MIPS_DWARF); 264 STRINGIFY_ENUM_CASE(ELF, SHT_MIPS_ABIFLAGS); 265 } 266 break; 267 case ELF::EM_MSP430: 268 switch (Type) { STRINGIFY_ENUM_CASE(ELF, SHT_MSP430_ATTRIBUTES); } 269 break; 270 case ELF::EM_RISCV: 271 switch (Type) { STRINGIFY_ENUM_CASE(ELF, SHT_RISCV_ATTRIBUTES); } 272 break; 273 default: 274 break; 275 } 276 277 switch (Type) { 278 STRINGIFY_ENUM_CASE(ELF, SHT_NULL); 279 STRINGIFY_ENUM_CASE(ELF, SHT_PROGBITS); 280 STRINGIFY_ENUM_CASE(ELF, SHT_SYMTAB); 281 STRINGIFY_ENUM_CASE(ELF, SHT_STRTAB); 282 STRINGIFY_ENUM_CASE(ELF, SHT_RELA); 283 STRINGIFY_ENUM_CASE(ELF, SHT_HASH); 284 STRINGIFY_ENUM_CASE(ELF, SHT_DYNAMIC); 285 STRINGIFY_ENUM_CASE(ELF, SHT_NOTE); 286 STRINGIFY_ENUM_CASE(ELF, SHT_NOBITS); 287 STRINGIFY_ENUM_CASE(ELF, SHT_REL); 288 STRINGIFY_ENUM_CASE(ELF, SHT_SHLIB); 289 STRINGIFY_ENUM_CASE(ELF, SHT_DYNSYM); 290 STRINGIFY_ENUM_CASE(ELF, SHT_INIT_ARRAY); 291 STRINGIFY_ENUM_CASE(ELF, SHT_FINI_ARRAY); 292 STRINGIFY_ENUM_CASE(ELF, SHT_PREINIT_ARRAY); 293 STRINGIFY_ENUM_CASE(ELF, SHT_GROUP); 294 STRINGIFY_ENUM_CASE(ELF, SHT_SYMTAB_SHNDX); 295 STRINGIFY_ENUM_CASE(ELF, SHT_RELR); 296 STRINGIFY_ENUM_CASE(ELF, SHT_ANDROID_REL); 297 STRINGIFY_ENUM_CASE(ELF, SHT_ANDROID_RELA); 298 STRINGIFY_ENUM_CASE(ELF, SHT_ANDROID_RELR); 299 STRINGIFY_ENUM_CASE(ELF, SHT_LLVM_ODRTAB); 300 STRINGIFY_ENUM_CASE(ELF, SHT_LLVM_LINKER_OPTIONS); 301 STRINGIFY_ENUM_CASE(ELF, SHT_LLVM_CALL_GRAPH_PROFILE); 302 STRINGIFY_ENUM_CASE(ELF, SHT_LLVM_ADDRSIG); 303 STRINGIFY_ENUM_CASE(ELF, SHT_LLVM_DEPENDENT_LIBRARIES); 304 STRINGIFY_ENUM_CASE(ELF, SHT_LLVM_SYMPART); 305 STRINGIFY_ENUM_CASE(ELF, SHT_LLVM_PART_EHDR); 306 STRINGIFY_ENUM_CASE(ELF, SHT_LLVM_PART_PHDR); 307 STRINGIFY_ENUM_CASE(ELF, SHT_LLVM_BB_ADDR_MAP_V0); 308 STRINGIFY_ENUM_CASE(ELF, SHT_LLVM_BB_ADDR_MAP); 309 STRINGIFY_ENUM_CASE(ELF, SHT_LLVM_OFFLOADING); 310 STRINGIFY_ENUM_CASE(ELF, SHT_GNU_ATTRIBUTES); 311 STRINGIFY_ENUM_CASE(ELF, SHT_GNU_HASH); 312 STRINGIFY_ENUM_CASE(ELF, SHT_GNU_verdef); 313 STRINGIFY_ENUM_CASE(ELF, SHT_GNU_verneed); 314 STRINGIFY_ENUM_CASE(ELF, SHT_GNU_versym); 315 default: 316 return "Unknown"; 317 } 318 } 319 320 template <class ELFT> 321 std::vector<typename ELFT::Rel> 322 ELFFile<ELFT>::decode_relrs(Elf_Relr_Range relrs) const { 323 // This function decodes the contents of an SHT_RELR packed relocation 324 // section. 325 // 326 // Proposal for adding SHT_RELR sections to generic-abi is here: 327 // https://groups.google.com/forum/#!topic/generic-abi/bX460iggiKg 328 // 329 // The encoded sequence of Elf64_Relr entries in a SHT_RELR section looks 330 // like [ AAAAAAAA BBBBBBB1 BBBBBBB1 ... AAAAAAAA BBBBBB1 ... ] 331 // 332 // i.e. start with an address, followed by any number of bitmaps. The address 333 // entry encodes 1 relocation. The subsequent bitmap entries encode up to 63 334 // relocations each, at subsequent offsets following the last address entry. 335 // 336 // The bitmap entries must have 1 in the least significant bit. The assumption 337 // here is that an address cannot have 1 in lsb. Odd addresses are not 338 // supported. 339 // 340 // Excluding the least significant bit in the bitmap, each non-zero bit in 341 // the bitmap represents a relocation to be applied to a corresponding machine 342 // word that follows the base address word. The second least significant bit 343 // represents the machine word immediately following the initial address, and 344 // each bit that follows represents the next word, in linear order. As such, 345 // a single bitmap can encode up to 31 relocations in a 32-bit object, and 346 // 63 relocations in a 64-bit object. 347 // 348 // This encoding has a couple of interesting properties: 349 // 1. Looking at any entry, it is clear whether it's an address or a bitmap: 350 // even means address, odd means bitmap. 351 // 2. Just a simple list of addresses is a valid encoding. 352 353 Elf_Rel Rel; 354 Rel.r_info = 0; 355 Rel.setType(getRelativeRelocationType(), false); 356 std::vector<Elf_Rel> Relocs; 357 358 // Word type: uint32_t for Elf32, and uint64_t for Elf64. 359 using Addr = typename ELFT::uint; 360 361 Addr Base = 0; 362 for (Elf_Relr R : relrs) { 363 typename ELFT::uint Entry = R; 364 if ((Entry & 1) == 0) { 365 // Even entry: encodes the offset for next relocation. 366 Rel.r_offset = Entry; 367 Relocs.push_back(Rel); 368 // Set base offset for subsequent bitmap entries. 369 Base = Entry + sizeof(Addr); 370 } else { 371 // Odd entry: encodes bitmap for relocations starting at base. 372 for (Addr Offset = Base; (Entry >>= 1) != 0; Offset += sizeof(Addr)) 373 if ((Entry & 1) != 0) { 374 Rel.r_offset = Offset; 375 Relocs.push_back(Rel); 376 } 377 Base += (CHAR_BIT * sizeof(Entry) - 1) * sizeof(Addr); 378 } 379 } 380 381 return Relocs; 382 } 383 384 template <class ELFT> 385 Expected<std::vector<typename ELFT::Rela>> 386 ELFFile<ELFT>::android_relas(const Elf_Shdr &Sec) const { 387 // This function reads relocations in Android's packed relocation format, 388 // which is based on SLEB128 and delta encoding. 389 Expected<ArrayRef<uint8_t>> ContentsOrErr = getSectionContents(Sec); 390 if (!ContentsOrErr) 391 return ContentsOrErr.takeError(); 392 ArrayRef<uint8_t> Content = *ContentsOrErr; 393 if (Content.size() < 4 || Content[0] != 'A' || Content[1] != 'P' || 394 Content[2] != 'S' || Content[3] != '2') 395 return createError("invalid packed relocation header"); 396 DataExtractor Data(Content, isLE(), ELFT::Is64Bits ? 8 : 4); 397 DataExtractor::Cursor Cur(/*Offset=*/4); 398 399 uint64_t NumRelocs = Data.getSLEB128(Cur); 400 uint64_t Offset = Data.getSLEB128(Cur); 401 uint64_t Addend = 0; 402 403 if (!Cur) 404 return std::move(Cur.takeError()); 405 406 std::vector<Elf_Rela> Relocs; 407 Relocs.reserve(NumRelocs); 408 while (NumRelocs) { 409 uint64_t NumRelocsInGroup = Data.getSLEB128(Cur); 410 if (!Cur) 411 return std::move(Cur.takeError()); 412 if (NumRelocsInGroup > NumRelocs) 413 return createError("relocation group unexpectedly large"); 414 NumRelocs -= NumRelocsInGroup; 415 416 uint64_t GroupFlags = Data.getSLEB128(Cur); 417 bool GroupedByInfo = GroupFlags & ELF::RELOCATION_GROUPED_BY_INFO_FLAG; 418 bool GroupedByOffsetDelta = GroupFlags & ELF::RELOCATION_GROUPED_BY_OFFSET_DELTA_FLAG; 419 bool GroupedByAddend = GroupFlags & ELF::RELOCATION_GROUPED_BY_ADDEND_FLAG; 420 bool GroupHasAddend = GroupFlags & ELF::RELOCATION_GROUP_HAS_ADDEND_FLAG; 421 422 uint64_t GroupOffsetDelta; 423 if (GroupedByOffsetDelta) 424 GroupOffsetDelta = Data.getSLEB128(Cur); 425 426 uint64_t GroupRInfo; 427 if (GroupedByInfo) 428 GroupRInfo = Data.getSLEB128(Cur); 429 430 if (GroupedByAddend && GroupHasAddend) 431 Addend += Data.getSLEB128(Cur); 432 433 if (!GroupHasAddend) 434 Addend = 0; 435 436 for (uint64_t I = 0; Cur && I != NumRelocsInGroup; ++I) { 437 Elf_Rela R; 438 Offset += GroupedByOffsetDelta ? GroupOffsetDelta : Data.getSLEB128(Cur); 439 R.r_offset = Offset; 440 R.r_info = GroupedByInfo ? GroupRInfo : Data.getSLEB128(Cur); 441 if (GroupHasAddend && !GroupedByAddend) 442 Addend += Data.getSLEB128(Cur); 443 R.r_addend = Addend; 444 Relocs.push_back(R); 445 } 446 if (!Cur) 447 return std::move(Cur.takeError()); 448 } 449 450 return Relocs; 451 } 452 453 template <class ELFT> 454 std::string ELFFile<ELFT>::getDynamicTagAsString(unsigned Arch, 455 uint64_t Type) const { 456 #define DYNAMIC_STRINGIFY_ENUM(tag, value) \ 457 case value: \ 458 return #tag; 459 460 #define DYNAMIC_TAG(n, v) 461 switch (Arch) { 462 case ELF::EM_AARCH64: 463 switch (Type) { 464 #define AARCH64_DYNAMIC_TAG(name, value) DYNAMIC_STRINGIFY_ENUM(name, value) 465 #include "llvm/BinaryFormat/DynamicTags.def" 466 #undef AARCH64_DYNAMIC_TAG 467 } 468 break; 469 470 case ELF::EM_HEXAGON: 471 switch (Type) { 472 #define HEXAGON_DYNAMIC_TAG(name, value) DYNAMIC_STRINGIFY_ENUM(name, value) 473 #include "llvm/BinaryFormat/DynamicTags.def" 474 #undef HEXAGON_DYNAMIC_TAG 475 } 476 break; 477 478 case ELF::EM_MIPS: 479 switch (Type) { 480 #define MIPS_DYNAMIC_TAG(name, value) DYNAMIC_STRINGIFY_ENUM(name, value) 481 #include "llvm/BinaryFormat/DynamicTags.def" 482 #undef MIPS_DYNAMIC_TAG 483 } 484 break; 485 486 case ELF::EM_PPC: 487 switch (Type) { 488 #define PPC_DYNAMIC_TAG(name, value) DYNAMIC_STRINGIFY_ENUM(name, value) 489 #include "llvm/BinaryFormat/DynamicTags.def" 490 #undef PPC_DYNAMIC_TAG 491 } 492 break; 493 494 case ELF::EM_PPC64: 495 switch (Type) { 496 #define PPC64_DYNAMIC_TAG(name, value) DYNAMIC_STRINGIFY_ENUM(name, value) 497 #include "llvm/BinaryFormat/DynamicTags.def" 498 #undef PPC64_DYNAMIC_TAG 499 } 500 break; 501 502 case ELF::EM_RISCV: 503 switch (Type) { 504 #define RISCV_DYNAMIC_TAG(name, value) DYNAMIC_STRINGIFY_ENUM(name, value) 505 #include "llvm/BinaryFormat/DynamicTags.def" 506 #undef RISCV_DYNAMIC_TAG 507 } 508 break; 509 } 510 #undef DYNAMIC_TAG 511 switch (Type) { 512 // Now handle all dynamic tags except the architecture specific ones 513 #define AARCH64_DYNAMIC_TAG(name, value) 514 #define MIPS_DYNAMIC_TAG(name, value) 515 #define HEXAGON_DYNAMIC_TAG(name, value) 516 #define PPC_DYNAMIC_TAG(name, value) 517 #define PPC64_DYNAMIC_TAG(name, value) 518 #define RISCV_DYNAMIC_TAG(name, value) 519 // Also ignore marker tags such as DT_HIOS (maps to DT_VERNEEDNUM), etc. 520 #define DYNAMIC_TAG_MARKER(name, value) 521 #define DYNAMIC_TAG(name, value) case value: return #name; 522 #include "llvm/BinaryFormat/DynamicTags.def" 523 #undef DYNAMIC_TAG 524 #undef AARCH64_DYNAMIC_TAG 525 #undef MIPS_DYNAMIC_TAG 526 #undef HEXAGON_DYNAMIC_TAG 527 #undef PPC_DYNAMIC_TAG 528 #undef PPC64_DYNAMIC_TAG 529 #undef RISCV_DYNAMIC_TAG 530 #undef DYNAMIC_TAG_MARKER 531 #undef DYNAMIC_STRINGIFY_ENUM 532 default: 533 return "<unknown:>0x" + utohexstr(Type, true); 534 } 535 } 536 537 template <class ELFT> 538 std::string ELFFile<ELFT>::getDynamicTagAsString(uint64_t Type) const { 539 return getDynamicTagAsString(getHeader().e_machine, Type); 540 } 541 542 template <class ELFT> 543 Expected<typename ELFT::DynRange> ELFFile<ELFT>::dynamicEntries() const { 544 ArrayRef<Elf_Dyn> Dyn; 545 546 auto ProgramHeadersOrError = program_headers(); 547 if (!ProgramHeadersOrError) 548 return ProgramHeadersOrError.takeError(); 549 550 for (const Elf_Phdr &Phdr : *ProgramHeadersOrError) { 551 if (Phdr.p_type == ELF::PT_DYNAMIC) { 552 Dyn = ArrayRef(reinterpret_cast<const Elf_Dyn *>(base() + Phdr.p_offset), 553 Phdr.p_filesz / sizeof(Elf_Dyn)); 554 break; 555 } 556 } 557 558 // If we can't find the dynamic section in the program headers, we just fall 559 // back on the sections. 560 if (Dyn.empty()) { 561 auto SectionsOrError = sections(); 562 if (!SectionsOrError) 563 return SectionsOrError.takeError(); 564 565 for (const Elf_Shdr &Sec : *SectionsOrError) { 566 if (Sec.sh_type == ELF::SHT_DYNAMIC) { 567 Expected<ArrayRef<Elf_Dyn>> DynOrError = 568 getSectionContentsAsArray<Elf_Dyn>(Sec); 569 if (!DynOrError) 570 return DynOrError.takeError(); 571 Dyn = *DynOrError; 572 break; 573 } 574 } 575 576 if (!Dyn.data()) 577 return ArrayRef<Elf_Dyn>(); 578 } 579 580 if (Dyn.empty()) 581 return createError("invalid empty dynamic section"); 582 583 if (Dyn.back().d_tag != ELF::DT_NULL) 584 return createError("dynamic sections must be DT_NULL terminated"); 585 586 return Dyn; 587 } 588 589 template <class ELFT> 590 Expected<const uint8_t *> 591 ELFFile<ELFT>::toMappedAddr(uint64_t VAddr, WarningHandler WarnHandler) const { 592 auto ProgramHeadersOrError = program_headers(); 593 if (!ProgramHeadersOrError) 594 return ProgramHeadersOrError.takeError(); 595 596 llvm::SmallVector<Elf_Phdr *, 4> LoadSegments; 597 598 for (const Elf_Phdr &Phdr : *ProgramHeadersOrError) 599 if (Phdr.p_type == ELF::PT_LOAD) 600 LoadSegments.push_back(const_cast<Elf_Phdr *>(&Phdr)); 601 602 auto SortPred = [](const Elf_Phdr_Impl<ELFT> *A, 603 const Elf_Phdr_Impl<ELFT> *B) { 604 return A->p_vaddr < B->p_vaddr; 605 }; 606 if (!llvm::is_sorted(LoadSegments, SortPred)) { 607 if (Error E = 608 WarnHandler("loadable segments are unsorted by virtual address")) 609 return std::move(E); 610 llvm::stable_sort(LoadSegments, SortPred); 611 } 612 613 const Elf_Phdr *const *I = llvm::upper_bound( 614 LoadSegments, VAddr, [](uint64_t VAddr, const Elf_Phdr_Impl<ELFT> *Phdr) { 615 return VAddr < Phdr->p_vaddr; 616 }); 617 618 if (I == LoadSegments.begin()) 619 return createError("virtual address is not in any segment: 0x" + 620 Twine::utohexstr(VAddr)); 621 --I; 622 const Elf_Phdr &Phdr = **I; 623 uint64_t Delta = VAddr - Phdr.p_vaddr; 624 if (Delta >= Phdr.p_filesz) 625 return createError("virtual address is not in any segment: 0x" + 626 Twine::utohexstr(VAddr)); 627 628 uint64_t Offset = Phdr.p_offset + Delta; 629 if (Offset >= getBufSize()) 630 return createError("can't map virtual address 0x" + 631 Twine::utohexstr(VAddr) + " to the segment with index " + 632 Twine(&Phdr - (*ProgramHeadersOrError).data() + 1) + 633 ": the segment ends at 0x" + 634 Twine::utohexstr(Phdr.p_offset + Phdr.p_filesz) + 635 ", which is greater than the file size (0x" + 636 Twine::utohexstr(getBufSize()) + ")"); 637 638 return base() + Offset; 639 } 640 641 template <class ELFT> 642 Expected<std::vector<BBAddrMap>> 643 ELFFile<ELFT>::decodeBBAddrMap(const Elf_Shdr &Sec) const { 644 Expected<ArrayRef<uint8_t>> ContentsOrErr = getSectionContents(Sec); 645 if (!ContentsOrErr) 646 return ContentsOrErr.takeError(); 647 ArrayRef<uint8_t> Content = *ContentsOrErr; 648 DataExtractor Data(Content, isLE(), ELFT::Is64Bits ? 8 : 4); 649 std::vector<BBAddrMap> FunctionEntries; 650 651 DataExtractor::Cursor Cur(0); 652 Error ULEBSizeErr = Error::success(); 653 // Helper to extract and decode the next ULEB128 value as uint32_t. 654 // Returns zero and sets ULEBSizeErr if the ULEB128 value exceeds the uint32_t 655 // limit. 656 // Also returns zero if ULEBSizeErr is already in an error state. 657 auto ReadULEB128AsUInt32 = [&Data, &Cur, &ULEBSizeErr]() -> uint32_t { 658 // Bail out and do not extract data if ULEBSizeErr is already set. 659 if (ULEBSizeErr) 660 return 0; 661 uint64_t Offset = Cur.tell(); 662 uint64_t Value = Data.getULEB128(Cur); 663 if (Value > UINT32_MAX) { 664 ULEBSizeErr = createError( 665 "ULEB128 value at offset 0x" + Twine::utohexstr(Offset) + 666 " exceeds UINT32_MAX (0x" + Twine::utohexstr(Value) + ")"); 667 return 0; 668 } 669 return static_cast<uint32_t>(Value); 670 }; 671 672 uint8_t Version = 0; 673 while (!ULEBSizeErr && Cur && Cur.tell() < Content.size()) { 674 if (Sec.sh_type == ELF::SHT_LLVM_BB_ADDR_MAP) { 675 Version = Data.getU8(Cur); 676 if (!Cur) 677 break; 678 if (Version > 2) 679 return createError("unsupported SHT_LLVM_BB_ADDR_MAP version: " + 680 Twine(static_cast<int>(Version))); 681 Data.getU8(Cur); // Feature byte 682 } 683 uintX_t Address = static_cast<uintX_t>(Data.getAddress(Cur)); 684 uint32_t NumBlocks = ReadULEB128AsUInt32(); 685 std::vector<BBAddrMap::BBEntry> BBEntries; 686 uint32_t PrevBBEndOffset = 0; 687 for (uint32_t BlockIndex = 0; 688 !ULEBSizeErr && Cur && (BlockIndex < NumBlocks); ++BlockIndex) { 689 uint32_t ID = Version >= 2 ? ReadULEB128AsUInt32() : BlockIndex; 690 uint32_t Offset = ReadULEB128AsUInt32(); 691 uint32_t Size = ReadULEB128AsUInt32(); 692 uint32_t Metadata = ReadULEB128AsUInt32(); 693 if (Version >= 1) { 694 // Offset is calculated relative to the end of the previous BB. 695 Offset += PrevBBEndOffset; 696 PrevBBEndOffset = Offset + Size; 697 } 698 BBEntries.push_back({ID, Offset, Size, Metadata}); 699 } 700 FunctionEntries.push_back({Address, std::move(BBEntries)}); 701 } 702 // Either Cur is in the error state, or ULEBSizeError is set (not both), but 703 // we join the two errors here to be safe. 704 if (!Cur || ULEBSizeErr) 705 return joinErrors(Cur.takeError(), std::move(ULEBSizeErr)); 706 return FunctionEntries; 707 } 708 709 template class llvm::object::ELFFile<ELF32LE>; 710 template class llvm::object::ELFFile<ELF32BE>; 711 template class llvm::object::ELFFile<ELF64LE>; 712 template class llvm::object::ELFFile<ELF64BE>; 713